A Design and Implementation of Spatial Database Based on XML-SVG

Jianting WEN Yan LI Youguang JIAN

Computer Science Deparment, South China Normal University

(Gaungzhou 510631)

XML, the Extensible Markup Language, is considered to be the second generation of network publishing language. For its expansibility, it is provided various applications such as GML, SVG etc based on XML Schema by W3C. SVG, which stands for Scalable Vector Graphics, is an open standard in text that makes it possible to represent graphic information in compact, portable form and mostly faces on the issuance of network spatial vector graphics.

In practice, It's impossible to avoid a great capacity of spatial data processing which had made SVG document is too big to be implemented during publishing on the Internet. It is slowed down the speed of the system execution through the Internet and is weaken its advantages and superiority. SVG database has been proposed as the solution for managing all the graphics and its attributes. In order to make the network issuance system which is based on XML-SVG circulating normally, first, an index map was compartmentalized SVG Document into different levels according to administrated district, international nomenclature, graphic layers correspondingly, and made an index table of database system. Secondly, a series of tables such as graphic elements, attributes, properties, character data and documents respectively in a more tiny granularity so that the spatial data and attributes have been combined and stored together. And customers can inquire about information of what he wants without the pressure of network transmission and the high configure of hardware.

In this research, Oracle was used to build the database system. Sever takes out data from the database with ASP.NET. Clients can access SVG Document embed in HTML through JavaScript. Dynamic and alternation of SVG are possible by use of a supplemental scripting language, such as JavaSript, which accesses DOM (SVG Document Object Model), which provides complete access to all elements, attributes and properties which even can be edited or replaced. This paper has been proved by the spatial information system of Guangdong Province. The inquiry efficiency has been improved to a great extent.

Key words: XML-SVG, spatial database, spatial information system